EXHAUST EMISSION CONTROL DEVICE

To suppress reduction in delivery pressure of urea water delivered from a urea supply device in start-up operation and to suppress freezing of urea water in a urea water filter.SOLUTION: An exhaust emission control device 14 comprises a urea selective reduction catalyst 21, a urea water jet valve 24, a urea water tank 25, a urea water pipe conduit 26, a urea water supply device 30, and a urea water filter 34. A heater 37 for thawing the urea water frozen in the filter case 35 is provided at the center position (axial center position) in the filter case 35 constituting the urea water filter 34. The urea water pipe conduit 26 is constituted of: a tank side urea water pipe conduit 27 having one end 27A connected to the urea water tank 25 and the other end 27B opening to a bottom surface of the filter case 35 in a post-filtration chamber 35E; and a jet valve side urea water pipe conduit 28 having one end 28A opening to an upper surface of a filter case 35 in a post-filtration chamber 35F and the other end 28B connected to the urea water jet valve 24.SELECTED DRAWING: Figure 4 【課題】スタートアップ動作において尿素供給装置から吐出される尿素水の吐出圧の低下を抑え、かつ尿素水フィルタ内での尿素水の凍結を抑える。【解決手段】排気ガス浄化装置１４は、尿素選択還元触媒２１、尿素水噴射弁２４、尿素水タンク２５、尿素水管路２６、尿素水供給装置３０、尿素水フィルタ３４を備える。尿素水フィルタ３４を構成するフィルタケース３５内の中央部（軸中心位置）には、フィルタケース３５内で凍結した尿素水を解凍するヒータ３７が設けられ、尿素水管路２６は、一端２７Ａが尿素水タンク２５に接続され、他端２７Ｂが濾過前室３５Ｅ内でフィルタケース３５の底面位置に開口したタンク側尿素水管路２７と、一端２８Ａが濾過後室３５Ｆ内でフィルタケース３５の上面位置に開口し、他端２８Ｂが尿素水噴射弁２４に接続された噴射弁側尿素水管路２８とにより構成される。【選択図】図４